That depends on your current consumption. Usually when we size a compressor we suggest a unit slightly larger than the current air tools require. That futureproofs your air compressor to some extent and ensures that you do have some room for expansion without having to replace the compressor.
There is, however, a limit to your expansion capabilities. To find the spare capacity in your compressed air system, add up the current consumption in CFM (cubic feet per minute) then subtract that amount from the CFM generated by your air compressor. Now compare that figure with the required CFM of the any new equipment you wish to add. If the amount required by the new tool is higher than the remaining CFM capacity, you’ll need to explore bringing in a new air compressor with greater capacity.
Bear in mind also that bar pressure affects the amount of CFM produced – the higher the bar required the lower the CFM.